Wheatear Research Articles

Study of Optimum Time Span for Distinguishing Rumex spinosus in Wheat Crop Through Spectral Reflectance Characteristics

Using the inherent spatial and temporal variability within a field to manage farm operations is called precision agriculture. This is a site-specific approach which can reduce input costs and results in higher crop productivity, profitability and lesser environmental pollution. Remote sensing provides a means for the development of weed maps by detecting the location of weeds within an agricultural field, so that site-specific/need based herbicide can be applied. Reductions in herbicide use as a result of this practice reduce management costs for farmers and promote environmental friendliness. The results revealed a decreasing trend in the number of tillers, effective tillers, number of grains per ear, 1,000-grain weight and grain yield of wheat with increasing population densities of Rumex spinosus (from 3 to 12 plants m−2). Highest grain yield of wheat (5.75 tonnes ha−1) was recorded under solid stand of wheat and lowest grain yield was recorded in treatments having 12 plants of R. spinosus. Higher radiance ratio and NDVI values were recorded in solid stand or pure wheat treatment and minimum under solid weed plots. It was observed that by using radiance ratio and NDVI, pure wheat can be distinguished from pure populations of R. spinosus after 30 DAS. It remains distinguished upto 120 DAS. Different levels of Rumex populations can be discriminated amongst themselves from 60 DAS onwards.

Foreign body aspiration in children: Experience from 2624 patients

ObjectivesThe objective of this study is to analyze the epidemiological, clinical, radiological and endoscopic characteristics of pediatric foreign body aspiration in Algeria. MethodsIn this retrospective study, the results of 2624 children younger than 18 years admitted in our department for respiratory foreign body removal between 1989 and 2012, were presented. Most of them had an ambulatory rigid bronchoscopy. ResultsThe children (62.34% males and 37.65% females) were aged 4 months to 18 years with 66% between 1 and 3 years. Choking was related in 65% of cases. The delay between aspiration and removal was 2–8 days in 65.8% and within 24h in 9.2%. In the most cases, the children arrived with cough, laryngeal or bronchial signs and unilateral reduction of vesicular murmur. The examination was normal in 13%. The most common radiologic finding was pulmonary air trapping (40.7%). The aspirated bodies were organic in 66.7%, dominated by peanuts, while sunflower seeds, beans and ears of wheat were the most dangerous. In the other cases, they were metallic or plastic as pen caps and recently scarf pins. The endoscopic removal by rigid bronchoscopy was successful and complete in 97%. Cases with extraction failure (3%) limited to certain FBs, all of them inorganic were assigned to surgery. The complications related to the endoscopic procedure were 0.29% with a mortality of 0.26%. ConclusionForeign body aspiration is a real public health problem in Algeria. The best way to manage it is an early diagnosis and a rigid bronchoscopy removal under general anesthesia used by fully trained staff. The prevention of this domestic accident should consider the population lifestyle and cultural habits to be more effective.

Surface feature based classification of plant organs from 3D laserscanned point clouds for plant phenotyping.

BackgroundLaserscanning recently has become a powerful and common method for plant parameterization and plant growth observation on nearly every scale range. However, 3D measurements with high accuracy, spatial resolution and speed result in a multitude of points that require processing and analysis. The primary objective of this research has been to establish a reliable and fast technique for high throughput phenotyping using differentiation, segmentation and classification of single plants by a fully automated system. In this report, we introduce a technique for automated classification of point clouds of plants and present the applicability for plant parameterization.ResultsA surface feature histogram based approach from the field of robotics was adapted to close-up laserscans of plants. Local geometric point features describe class characteristics, which were used to distinguish among different plant organs. This approach has been proven and tested on several plant species. Grapevine stems and leaves were classified with an accuracy of up to 98%. The proposed method was successfully transferred to 3D-laserscans of wheat plants for yield estimation. Wheat ears were separated with an accuracy of 96% from other plant organs. Subsequently, the ear volume was calculated and correlated to the ear weight, the kernel weights and the number of kernels. Furthermore the impact of the data resolution was evaluated considering point to point distances between 0.3 and 4.0 mm with respect to the classification accuracy.ConclusionWe introduced an approach using surface feature histograms for automated plant organ parameterization. Highly reliable classification results of about 96% for the separation of grapevine and wheat organs have been obtained. This approach was found to be independent of the point to point distance and applicable to multiple plant species. Its reliability, flexibility and its high order of automation make this method well suited for the demands of high throughput phenotyping.Highlights• Automatic classification of plant organs using geometrical surface information• Transfer of analysis methods for low resolution point clouds to close-up laser measurements of plants• Analysis of 3D-data requirements for automated plant organ classification

Mycotoxin production, chemotypes and diversity of Czech Fusarium graminearum isolates on wheat

Fusarium head blight (FHB) is a serious cereal disease in the CzechRepublic. The most important pathogen associated with FBH is Fusarium graminearum, which can produce trichothecenes, mainly deoxynivalenol (DON) and its derivates. A set of 103 F. graminearum isolates were isolated from naturally infected wheat ears collected from 20 localities (25 ears from one locality) within the Czech Republic, in the year 2004. The ears were evaluated for DON content by ELISA. Maximum detected value was 30.7 mg/kg. A group of PCR assays targeting the segments of the Tri7, Tri13 and Tri3 genes were used to determine the chemotypes of F. graminearum isolates. All the isolates belonged to DON producing chemotype. Further discrimination revealed that almost all (99.03%) isolates belonged to 15-ADON chemotype, and only one (0.97%) isolate belonged to 3-ADON chemotype. The genetic variability of the isolates was assessed from their AFLP fingerprints. The populations were highly heterogeneous both within and between locations, and no clear evidence for the association between AFLP profile and geographic origin was found out.    

Mechanisms Regulating Grain Contamination with Trichothecenes Translocated from the Stem Base of Wheat (Triticum aestivum) Infected withFusarium culmorum

Factors limiting trichothecene contamination of mature wheat grains after Fusarium infection are of major interest in crop production. In addition to ear infection, systemic translocation of deoxynivalenol (DON) may contribute to mycotoxin levels in grains after stem base infection with toxigenic Fusarium spp. However, the exact and potential mechanisms regulating DON translocation into wheat grains from the plant base are still unknown. We analyzed two wheat cultivars differing in susceptibility to Fusarium head blight (FHB), which were infected at the stem base with Fusarium culmorum in climate chamber experiments. Fungal DNA was found only in the infected stem base tissue, whereas DON and its derivative, DON-3-glucoside (D3G), were detected in upper plant parts. Although infected stem bases contained more than 10,000 μg kg⁻¹ dry weight (DW) of DON and mean levels of DON after translocation in the ear and husks reached 1,900 μg kg⁻¹ DW, no DON or D3G was detectable in mature grains. D3G quantification revealed that DON detoxification took mainly place in the stem basis, where ≤ 50% of DON was metabolized into D3G. Enhanced expression of a gene putatively encoding a uridine diphosphate-glycosyltransferase (GenBank accession number FG985273) was observed in the stem base after infection with F. culmorum. Resistance to F. culmorum stem base infection, DON glycosylation in the stem base, and mycotoxin translocation were unrelated to cultivar resistance to FHB. Histological studies demonstrated that the vascular transport of DON labeled with fluorescein as a tracer from the peduncle to the grain was interrupted by a barrier zone at the interface between grain and rachilla, formerly described as "xylem discontinuity". This is the first study to demonstrate the effective control of influx of systemically translocated fungal mycotoxins into grains at the rachilla-seed interface by the xylem discontinuity tissue in wheat ears.

Yeni Hitit Sanatı Üzerine İkonografik Araştırmalar (1): Üzüm Salkımı ve/veya Başak Filizi Taşıyanlar

This article concerns the representations of figures holding a bunch of grapes and/or ears of wheat which are frequently found in Neo-Hittite Art. In this context, the main focus is upon the question as to why these representations came to be commonly depicted during the first millennium in Neo-Hittite Art. This issue has been investigated and analysed within the framework of possibilities provided by the principles of iconographic research, under the titles of form, meaning, content, very similar and similar examples and concludes with the evaluation of the collected data within the context of research results from different branches.

Host Impact and Specificity of Tortoise Beetle (Cassida rubiginosa) on Canada Thistle (Cirsium arvense) in Iran

This study determined the potential of the tortoise beetle (Coleoptera: Chrysomelidae) to control Canada thistle (Asteraceae) in Iran. Genetic analysis of the tortoise beetle, based on mitochondrial DNA, confirmed the presence of the species in Iran. A field experiment using five insect densities (0 to 20 larvae plant−1) showed a positive correlation between the number of larvae transferred and impact. Feeding by 20 larvae reduced total biomass of Canada thistle by 78% and the number of capitula by 94%. More important, when grown in competition with wheat, four and eight egg batches (corresponding to approximately 12 and 24 larvae) per Canada thistle plant increased wheat ear weight by 46 and 82%, respectively. Host range studies with 22 crop and 21 weed species using no-choice and multiple-choice tests under laboratory and field conditions and parallel data from a field survey showed that joint feeding and oviposition were restricted to Canada thistle and a few other weed species. Limited feeding, without oviposition, was recorded on an additional seven weed species but also on safflower (10 to 15% reduction in biomass), and common sunflower (< 10%); the latter only under no-choice conditions. The growing period of either crop species, however, does not coincide with the feeding period of the tortoise beetle in the field. Findings indicate that the tortoise beetle is a promising biological control agent for Canada thistle in arable crops and grasslands in Iran. Other complementary methods will likely be needed to prevent substantial yield losses.

Experiments with Lithic Tools: Understanding Starch Residues from Crop Harvesting

Stone knives were used widely in Neolithic East Asia, presumably in the harvesting of grain crops, but their function has not been clearly understood due to the lack of study of residues from these tools. To address this issue, starch grain analysis was employed to study the residues on the surface of ancient stone knives and large amounts of starches were recovered. The sources of these starches, however, were not well understood, because harvesting of crops involves the cutting of stems rather than direct contact with starchy seeds. To determine whether harvesting could deposit these types of residues, we designed a simulation experiment using stone flakes to harvest ears of wheat, rice and foxtail millet, then analysed the residues on both the flakes and in the plant tissues. A large number of starch grains were found in the stems, including both typical morphotypes from seeds and newly described types that occur only in stems, which can be used as indicators of harvesting. Our study demonstrates that starch grains from residues on the surfaces of archaeological stone knives can indicate not only that the tools were used to harvest ears, but also the type of crops harvested.

Alternaria mycotoxins in wheat – A 10 years survey in the Northeast of Germany

Although, the genus Alternaria is considered to be an important plant pathogen and capable to produce mycotoxins, the presence of Alternaria mycotoxins in cereals has been largely ignored both in Europe and overseas. This is very likely due to a lack of survey data. This study aimed at filling this gap by investigating a total of 1064 freshly harvested winter wheat samples from commercial farms in different regions of the State of Brandenburg (Germany) in the years from 2001 to 2010. We analysed alternariol (AOH), its monomethyl ether (AME), altenuene (ALT, since 2006) and tenuazonic acid (TeA) by a HPLC method with diode array and fluorescence detection. The most frequently found A. mycotoxin was TeA. An amount of 322 out of 1064 samples (30.3%) were naturally contaminated by TeA, 86 out of 1064 by AOH (8.1%), 33 out of 1064 by AME (3.1%) and 7 out of 267 samples (2.6%) were contaminated by ALT. The maximum toxin contents in all years were 4224 μg TeA kg−1, 832 μg AOH kg−1, 905 μg AME kg−1 and 197 μg ALT kg−1. A co-occurrence of several A. mycotoxins in wheat samples was infrequent: only three samples were contaminated by all the four toxins, 14 by three toxins, 61 by two toxins and 273 samples by only one toxin. The contamination of wheat ears in the State of Brandenburg in the wet years 2010, 2009 and 2002 were most pronounced, whereas 2001 and 2008 were A. “toxin free” years. The accumulation of TeA in freshly harvested wheat kernels seems to depend on preceding crop and tillage. Minimum tillage practices and maize as well as winter wheat as preceding crops led to increased TeA concentrations in wheat. A co-occurrence of mycotoxins produced by several mycotoxigenic fungi, e.g. Fusarium and Alternaria spp., is discussed.

Antibiosis and Non-preference of Sitobion avenae (F.) (Hemiptera: Aphididae) on Leaves and Ears of Commercial Cultivars of Wheat (Triticum aestivum)

Little is known on the resistance of wheat cultivars to Sitobion avenae (F.) in Brazil. The goal of this work was to assess the behavior and biology of S. avenae on four commercial wheat cultivars to verify the existence of resistance by antibiosis in leaves and ears and non-preference in the ears. The smallest net fecundity rates of S. avenae in wheat leaves have been found in the cultivars Embrapa 22 and BRS264, which did not differ between themselves. The intrinsic rate of increase of S. avenae was smaller in leaves of Embrapa 22 than in cultivars BRS254 and BRS Timbaúva. The smallest net fecundity rates of S. avenae in wheat ears were observed in the cultivars BRS254 and Embrapa 22. The intrinsic rate of increase of the aphid in the ear of cultivar Embrapa 22 was smaller than in BRS Timbaúva and BRS264, but did not differ from BRS254. The organ of the wheat plant in which the aphid was reared influences antibiosis resistance, but the cultivar BRS Timbaúva was considered susceptible and Embrapa 22 resistant to S. avenae in both plant organs tested. Ears of wheat cultivars tested did not show differences in the mechanism of resistance by non-preference to S. avenae.

Characterization of the sterol 14α‐demethylases of Fusarium graminearum identifies a novel genus‐specific CYP51 function

CYP51 encodes the cytochrome P450 sterol 14α-demethylase, an enzyme essential for sterol biosynthesis and the target of azole fungicides. In Fusarium species, including pathogens of humans and plants, three CYP51 paralogues have been identified with one unique to the genus. Currently, the functions of these three genes and the rationale for their conservation within the genus Fusarium are unknown. Three Fusarium graminearum CYP51s (FgCYP51s) were heterologously expressed in Saccharomyces cerevisiae. Single and double FgCYP51 deletion mutants were generated and the functions of the FgCYP51s were characterized in vitro and in planta. FgCYP51A and FgCYP51B can complement yeast CYP51 function, whereas FgCYP51C cannot. FgCYP51A deletion increases the sensitivity of F. graminearum to the tested azoles. In ΔFgCYP51B and ΔFgCYP51BC mutants, ascospore formation is blocked, and eburicol and two additional 14-methylated sterols accumulate. FgCYP51C deletion reduces virulence on host wheat ears. FgCYP51B encodes the enzyme primarily responsible for sterol 14α-demethylation, and plays an essential role in ascospore formation. FgCYP51A encodes an additional sterol 14α-demethylase, induced on ergosterol depletion and responsible for the intrinsic variation in azole sensitivity. FgCYP51C does not encode a sterol 14α-demethylase, but is required for full virulence on host wheat ears. This is the first example of the functional diversification of a fungal CYP51.

Health of leaves and ears of spring wheat (Triticum aestivum L.) cultivated after different forecrops

The research was conduced in the years 2000-2002. The aim of the research was to determinate the health of leaves and ears of spring wheat cultivated after spring cruciferae plants such as: spring oilseed rape (<i>Brassica napus</i> ssp. <i>oleiferus</i> Metz.), chiiiese mustard (<i>Brassica juncea</i> L.), white mustard (<i>Sinapis alba</i> L.), ole iferous radish (<i>Raphanus sativus</i> var. <i>oleiferus</i> L.), false flax (<i>Camelina sativa</i> L.), crambe (<i>Crambe abbysinica</i> Hoechst.), as well as after oat (<i>Avena sativa</i> L.) as con trol. Spring wheat cv. Torka was sown after: pIoughed stubble cultivated on this field, ploughed stubble and straw, ploughed stubble with straw and 30 kg nitrogen per hectare. During all the years of studies on leaves and ears of spring wheat septo ria of leaf blotch and glume blotch (<i>Mycosphaerella graminicola, Phaeosphaeria nodorum</i>) were found. Brown rust (<i>Puccinia recondita</i> f. sp. <i>tritici</i>) was seen on leaves of wheat only during years 2001-2002. Besides on ears fusarium ear blight (Fusarimn sp.) was present in 2002 and sooty mould (<i>Cladosporium sp., Alternaria</i> sp.) in 2001. According to health of overground parts of plants the good forecrops to spring wheat were oat, chinese mustard, oleiferous radish. The biggest impact on presence of diseases of leaves and ears had the weather during years of studies. The use of after harvest rests didn't have significant influence on health of leaves and ears of spring wheat.

Quantifying the relationship between temperature regulation in the ear and floret development stage in wheat (Triticum aestivum L.) under heat and drought stress.

Thermal imaging is a valuable tool for the clarification of gas exchange dynamics between a plant and its environment. The presence of stomata in wheat (Triticum aestivum L.) glumes and awns offers an opportunity to assess the photosynthetic activity of ears up to and during flowering. Knowledge of the spatial and temporal thermodynamics of the wheat ear may provide insight into interactions between floret developmental stage (FDS), temperature depression (TD) and ambient environment, with potential to use these as high-throughput screening tools for breeders. A controlled environment study was conducted using six spring wheat genotypes of the elite recombinant inbred line Seri-Babax. Average ear temperature was recorded using a hand-held infrared camera and gas exchange was measured by enclosing ears in a custom-built cuvette. FDS was monitored and recorded daily throughout the study. Plants were grown in pots and exposed to a combination of two temperature and two water regimes. In the studied wheat lines, TD varied from 0.1°C to 0.6°C according to the level of stress imposed. The results indicated that TD does not occur at FDS F3, the peak of active flowering, but during the stages before pollen release and stigma maturity (F1-F2). These findings suggest that ear temperature during the early stages of anthesis, before pollen release and full extension of the stigma, are likely to be the most relevant for identifying heat stress tolerant genotypes.

Effect of bixafen on senescence and yield formation of wheat

Bixafen, a pyrazole carboxamide inhibiting succinate dehydrogenase of the fungal respiratory chain, is a new broad-spectrum fungicide developed for the control of pathogens in cereals. The effects of bixafen on senescence and yield formation of wheat plants were studied and compared to those caused by azoles, strobilurins and spiroketalamins under disease-free conditions in the greenhouse. Fungicide applications delayed the appearance and senescence of wheat ears. Application of bixafen, fluoxastrobin and prothioconazole delayed also the senescence of leaves and significantly extended the green leaf area duration compared to untreated and spiroxamine treated plants. Differences in the senescence of leaves and ears between treatments were confirmed by measurements of the temperature of wheat tissue as an indicator of transpiration activity. Digital infrared images revealed significant differences between untreated and fungicide-treated plants at different growth stages (GS). At GS 75, photosynthetic activity of untreated plants was lower compared to fungicide-treated plants; however, only bixafen gave a significant effect. All fungicide treatments increased grain yield. Application of bixafen significantly increased the yield compared to all other treatments. The temperature of ears and leaves was negatively correlated to grain yield. Lower tissue temperature of fungicide-treated plants was a suitable indicator of tissue vitality and higher photosynthetic activity due to the retardation of ear and leaf senescence. The combination of positive effects on physiology of wheat resulted in a yield advantage of bixafen-treated plants.

Frost Hardiness Expression and Characterisation in Wheat at Ear Emergence

AbstractOccasionally, wheat can be exposed to overnight freezing temperatures whilst it is in the early reproductive stage and considerable frost damage can occur. In the vegetative stage, full expression of frost tolerance genes can be gained when plants are exposed to acclimation temperatures (4 °C). Paradoxically, wheat during flowering has limited or no ability to effectively acclimate or re‐acclimate and it demonstrates frost sensitivity during this stage. Using a combined approach involving infrared thermography and molecular analysis, the causes and effects of frost‐induced damage to wheat during ear emergence were investigated. It was demonstrated that frost damage only occurs to wheat ears if the temperature falls below −5 °C but some ears, and some spikelets on frozen ears do not freeze but supercool and escape freezing. In whole plant freezing experiments, spikelets showed both complete and partial sterility upon maturation and this was linked to parallel infrared observation of detached ears showing full or partial freezing of spikelets. It was hypothesised that wherever spikelet freezing occurred the spikelet was sterile and grain production per ear was drastically reduced, and in contrary, spikelet survival was as a result of supercooling. Molecular analysis of the upregulation of Cbf14 showed that as ear emergence progressed the ability to induce Cbf14 decreased but at early stages of ear emergence Cbf14 was able to be induced by exposure to acclimating temperatures (4 °C). The hypothesis that the lack of the ear to acclimate is because of the incapability to induce the CBF transcription factor was only partially upheld in this investigation. Further work is needed to elucidate more precisely the molecular incompetency for the acclimation of wheat during ear emergence.

Recognition of wheat preharvest sprouting based on hyperspectral imaging

An imaging spectrometer was used to acquire hyperspectral images of 120 strains of wheat ears and seeds under four different watering treatments. Whether wheat preharvest sprouting occurred could be reflected by spectral characteristics. Therefore, it was possible to judge whether wheat ears sprouted according to changes of spectral curve at 675 nm. According to principal component analysis of mean spectral reflectivity values of wheat seeds, it was found that wheat seeds watered three times every day and wheat seeds watered once every day were significantly different from nonsprouting wheat seeds soaked all day and original dry seeds due to significant sprouting situations, suggesting that imaging spectra can differentiate different extent of wheat preharvest sprouting. Glume had an influence on the hyperspectral images of wheat ears, therefore the hyperspectral images of wheat ears could be used to measure sprouting only when serious sprouting occurred. At an early stage of sprouting, only the hyperspectral images of wheat seeds could be used to analyze the sprouting of wheat.

Effect of Jasmonic Application on Economically Insect Pests and Yeald in Spring Wheat

Field trials were conducted in spring wheat to observe effects of jasmonic acid (JA) on aphids, thrips and wheat blossom midge (WBM). Two spring wheat varieties (Triso and Kadrilj) were sprayed twice, with two concentrations of JA plus control. Wheat pests and associated natural enemies (Coccinellidae, Empididae and Aphelinidae) were surveyed by direct count and sweep net methods. Thrips larvae and adults and WBM larvae were estimated by dissecting wheat ears. Wheat midge larvae were monitored using white traps in treated and untreated plots. At the end of season, wheat yield was assessed in treated and control plots. There was a significant difference in the number of insect pests and their natural enemies between treatments in both varieties. Plants in control plots had higher numbers of aphids, thrips and midges than in treated plots. There were more aphids, thrips and midges on the variety ‘Triso’ than on ‘Kadrilj’. JA application enhanced wheat yield in treated plots compared to control plots. The results indicated that JA mediated induction of plant defense in wheat plants can improve resistance against insect herbivores. JA could be used to develop environmentally sound crop management with reduced insecticide applications.

Fungicide protection and presence of fusarium ear symptoms and deoxynivalenol content in the grain of winter speltOchrona fungicydowa a obecność objawów fuzariozy kłosów i deoksyniwalenolu w ziarnie pszenicy ozimej orkisz

Summary Fusarium head blight (FHB) is perceived as a threat to wheat production. Besides the reduction of the yield potential of infected plants, the fungus contaminates kernels with different mycotoxins. The objective of our studies was to follow the development of Fusarium culmorum of FHB pathogen in winter spelt. Two fungicide experiments with and without inoculation was conducted in Winna Gora. F. culmorum was isolated from winter wheat ears with significally disease symptoms in 2009. The most aggressive isolate was used for inoculation of spelt in 2011. Colonisation of ears by F. culmorum was low in both experiments and no other Fusarium species could be detected. The used fungicides reduced significantly the level of infection but the concentration of deoxynivalenol (DON) in the grain was not correlated with Fusarium occurrence on ears and grain.

Algunos apuntes sobre la <i>Natividad</i> de Federico Barocci en el Museo del Prado

This text proposes a reading of Barocci’s Nativity in the Prado Museum as a Eucharistic allegory, due to the presence of ears of wheat, grain, and bread in the composition. The painting is studied in connection with its preparatory drawings (one of which, in the Louvre, has not been considered to date), and analyses Barocci’s working method: he must have modelled a sculpture inspired by the figure of Christ in Correggio’s Agony in the Garden in order to study the position of Mary.

Plant uptake of pesticides and human health: Dynamic modeling of residues in wheat and ingestion intake

Human intake of pesticide residues from consumption of processed food plays an important role for evaluating current agricultural practice. We take advantage of latest developments in crop-specific plant uptake modeling and propose an innovative dynamic model to estimate pesticide residues in the wheat-environment system, dynamiCROP. We used this model to analyze uptake and translocation of pesticides in wheat after foliar spray application and subsequent intake fractions by humans. Based on the evolution of residues in edible parts of harvested wheat we predict that between 22 mg and 2.1 g per kg applied pesticide are taken in by humans via consumption of processed wheat products. Model results were compared with experimentally derived concentrations in wheat ears and with estimated intake via inhalation and ingestion caused by indirect emissions, i.e. the amount lost to the environment during pesticide application. Modeled and measured concentrations in wheat fitted very well and deviate from less than a factor 1.5 for chlorothalonil to a maximum factor 3 for tebuconazole. Main aspects influencing pesticide fate behavior are degradation half-life in plant and time between pesticide application and crop harvest, leading to variations in harvest fraction of at least three orders of magnitude. Food processing may further reduce residues by approximately 63%. Intake fractions from residues in sprayed wheat were up to four orders of magnitude higher than intake fractions estimated from indirect emissions, thereby demonstrating the importance of exposure from consumption of food crops after direct pesticide treatment.